Adhesive composition, method for preparing the same, reticle assembly including the same, and method for fabricating reticle assembly including the same

ABSTRACT

An adhesive composition, a method for preparing the same, a reticle assembly including the same, and a method for fabricating the reticle assembly including the same are provided. The adhesive composition includes a polyphenol compound including tannic acid, a polymer including polyvinyl alcohol, and a solvent including water and alcohol.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2020-0144447 filed on Nov. 2, 2020 in the Korean IntellectualProperty Office, and all the benefits accruing therefrom under 35 U.S.C.119, the contents of which in its entirety are herein incorporated byreference.

BACKGROUND 1. Technical Field

The present disclosure relates to an adhesive composition, a method forpreparing the same, a reticle assembly including the same, and a methodfor preparing a reticle assembly including the same. More particularly,the present disclosure relates to a composition for a polyphenol-basedadhesive, a method for preparing the same, a reticle assembly includingthe same, and a method for fabricating a reticle assembly including thesame.

2. Description of the Related Art

Photolithography may be used to fabricate an electronic device such as asemiconductor device, and a reticle assembly and a pellicle forprotecting the reticle assembly may be used to perform thephotolithography.

The pellicle may include a pellicle membrane and a frame supporting thepellicle membrane. Meanwhile, the pellicle membrane and the frame, orthe frame and the reticle assembly may be bonded to each other by anadhesive. This adhesive requires strong adhesive strength and should becapable of being easily removed for pellicle replacement.

SUMMARY

Aspects of the present disclosure provide an adhesive composition thatis easily removed, is environmentally friendly and has strong adhesivestrength, and a method for preparing the same.

Aspects of the present disclosure also provide a reticle assembly usingan adhesive composition that can be easily removed, is environmentallyfriendly and has strong adhesive strength, and a method for fabricatingthe same.

However, aspects of the present disclosure are not restricted to thoseset forth herein. The above and other aspects of the present disclosurewill become more apparent to one of ordinary skill in the art to whichthe present disclosure pertains by referencing the detailed descriptionof the present disclosure given below.

According to an aspect of the present inventive concept, there isprovided an adhesive composition comprising a polyphenol compoundincluding tannic acid, a polymer including polyvinyl alcohol, and asolvent including water and alcohol.

According to an aspect of the present inventive concept, there isprovided an adhesive composition in a powder form, comprising apolyphenol compound including tannic acid, and a polymer includingpolyvinyl alcohol.

According to an aspect of the present inventive concept, there isprovided a method for preparing an adhesive composition, comprisingproviding an aqueous polyphenol solution including tannic acid,providing an aqueous polymer solution including polyvinyl alcohol,mixing the aqueous polyphenol solution with the aqueous polymer solutionto form a mixed aqueous solution, drying the mixed aqueous solution toform a powder composition, and dissolving the powder composition in asolvent including water and alcohol.

According to an aspect of the present inventive concept, there isprovided a reticle assembly comprising a photomask, a stud protrudingfrom the photomask, a pellicle adhesive layer configured to adhere thestud onto the photomask, and a pellicle fixed on the photomask by thestud, wherein the pellicle adhesive layer includes a polyphenol compoundincluding tannic acid and a polymer including polyvinyl alcohol.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present disclosure willbecome more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings, in which:

FIG. 1 is a flowchart illustrating a method for preparing an adhesivecomposition according to some embodiments.

FIG. 2 is a perspective view illustrating a reticle assembly includingan adhesive composition according to some embodiments.

FIG. 3 is a schematic cross-sectional view illustrating the reticleassembly of FIG. 2.

FIG. 4 is a conceptual diagram illustrating exposure equipment using thereticle assembly of FIGS. 2 and 3.

FIGS. 5 to 7 are diagrams illustrating the intermediate steps of amethod for fabricating a reticle assembly including an adhesivecomposition according to some embodiments.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Advantages and features of the present inventive concept and methods ofaccomplishing the same may be understood more readily by reference tothe following detailed description of preferred embodiments and theaccompanying drawings. The present inventive concept may, however, beembodied in many different forms and should not be construed as beinglimited to the embodiments set forth herein. Rather, these embodimentsare provided so that this disclosure will be thorough and complete andwill fully convey the concept of the inventive concept to those skilledin the art, and the present inventive concept will only be defined bythe appended claims. In the drawings, the thickness of layers andregions are exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on” or “connected to” another element or layer, it can bedirectly on or connected to the other element or layer or interveningelements or layers may be present. In contrast, when an element isreferred to as being “directly on” or “directly connected to” anotherelement or layer, there are no intervening elements or layers present.Like numbers refer to like elements throughout. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the inventive concept (especially in the contextof the following claims) are to be construed to cover both the singularand the plural, unless otherwise indicated herein or clearlycontradicted by context. The terms “comprising,” “having,” “including,”and “containing” are to be construed as open-ended terms (i.e., meaning“including, but not limited to,”) unless otherwise noted.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another element. Thus, for example, a first element, afirst component or a first section discussed below could be termed asecond element, a second component or a second section without departingfrom the teachings of the present inventive concept.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this inventive concept belongs. It is noted that theuse of any and all examples, or exemplary terms provided herein isintended merely to better illuminate the inventive concept and is not alimitation on the scope of the inventive concept unless otherwisespecified. Further, unless defined otherwise, all terms defined ingenerally used dictionaries may not be overly interpreted.

Adhesive composition

Hereinafter, an adhesive composition according to exemplary embodimentswill be described.

The adhesive composition according to some embodiments contains apolyphenol compound, a polymer and the balance of a solvent.

The polyphenol compound may include tannic acid (TA). The polyphenolcompound including tannic acid may be naturally obtained. The tannicacid may have a large molecular size and may include a plurality ofhydroxy groups. The tannic acid may be represented by Formula 1 below.

In some embodiments, the content of tannic acid may be about 5 wt % (%by weight) to about 45 wt % with respect to 100 wt % of the adhesivecomposition. Preferably, the content of tannic acid may be from about 10wt % to about 40 wt % with respect to 100 wt % of the adhesivecomposition. When the content of tannic acid is excessively low,sufficient adhesive strength cannot be provided. When the content oftannic acid is excessively high, the viscosity of the adhesivecomposition may increase excessively.

The polymer may include polyvinyl alcohol (PVA). The polyvinyl alcoholmay include a plurality of hydroxy groups. The polyvinyl alcohol may berepresented by Formula 2 below. In Formula 2 below, 1 is a naturalnumber of 2 or more.

The polyvinyl alcohol may be a fully hydrated polyvinyl alcohol, or maybe a copolymer including partially repeating units other than vinylalcohol. For example, the polyvinyl alcohol may include poly(vinylalcohol-co-vinyl acetate), represented by Formula 3 below. In Formula 3below, each of m and n is a natural number.

In some embodiments, the content of the polyvinyl alcohol may be about 5wt % to about 45 wt % with respect to 100 wt % of the adhesivecomposition. Preferably, the content of the polyvinyl alcohol may beabout 10 wt % to about 40 wt % with respect to 100 wt % of the adhesivecomposition. When the content of the polyvinyl alcohol is excessivelylow, sufficient adhesive strength cannot be provided. When the contentof the polyvinyl alcohol is excessively high, the viscosity of theadhesive composition may increase excessively.

In some embodiments, the polyvinyl alcohol may have a weight averagemolecular weight of about 8,000 to about 70,000. For example, the weightaverage molecular weight of the polyvinyl alcohol may be about 9,000 toabout 10,000. When the weight average molecular weight of the polyvinylalcohol is excessively low, sufficient adhesive strength cannot beprovided. When the weight average molecular weight of the polyvinylalcohol is excessively high, the viscosity of the adhesive compositionmay increase excessively.

In some embodiments, the ratio of the weight of the polyvinyl alcohol tothe weight of the tannic acid may be about 0.1 to about 10. Preferably,the ratio of the weight of the polyvinyl alcohol to the weight of thetannic acid may be about 0.5 to about 2.

The solvent may include water and alcohol. For example, the solvent maybe provided by adding alcohol as a co-solvent to water. The alcohol maybe, for example, ethanol, but is not limited thereto.

A polyphenol-based adhesive that uses only water as a solvent has aproblem in that a continuous phase separation phenomenon, such asprecipitation in a gel type, occurs. In addition, an organic solventsuch as alcohol used alone as a solvent has a problem of being incapableof easily dissolving a polyphenol compound and/or polymer. However, theadhesive composition according to some embodiments is capable ofpreventing a phase separation phenomenon and homogeneously dissolvingthe polyphenol compound and the polymer due to the use of the solventincluding the alcohol as a co-solvent. Accordingly, an adhesivecomposition that is provided in a liquid state, prevents a phaseseparation phenomenon and thus has increased pot life and improvedstorage properties, may be provided.

In some embodiments, the ratio of the weight of the alcohol to theweight of the water may be about 0.1 to about 10. Preferably, the ratioof the weight of the alcohol to the weight of the water may be about 0.5to about 2.

The adhesive composition according to some embodiments may berepresented by Formula 4 below. In Formula 4 below, the alcohol isethanol.

As shown in Formula 4 above, each of the tannic acid and the polyvinylalcohol may include a plurality of hydroxy groups, so the polyvinylalcohol may form hydrogen bonds with the tannic acid and be entangledtherewith. As a result, the adhesive composition containing the tannicacid and the polyvinyl alcohol may have an adhesive strength.

In addition, as shown in Formula 4 above, the solvent including waterand alcohol may form hydrogen bonds with the tannic acid and thepolyvinyl alcohol. Because the solvent includes the alcohol as aco-solvent, it may form a relatively small number of hydrogen bonds withthe tannic acid and the polyvinyl alcohol. For example, the adhesivecomposition according to some embodiments may form a relatively smallnumber of hydrogen bonds compared to an adhesive composition using onlywater as a solvent. For example, as shown in Formula 4 above, each watermolecule or each alcohol molecule of the adhesive composition accordingto some embodiments may form one to two hydrogen bonds with the tannicacid or the polyvinyl alcohol. In contrast, each water molecule of theadhesive composition using only water as a solvent may form three ormore hydrogen bonds with the tannic acid or the polyvinyl alcohol. As aresult, an adhesive composition that has controlled viscosity and thusimproved usability in the bonding process may be provided.

The adhesive composition according to some embodiments may furthercontain silicon oxide. The silicon oxide may, for example, includesilica particles. For example, the silicon oxide may include a silicanano-powder. The silica particles may, for example, have a size of about1 nm to about 100 μm, but are not limited thereto. The silica particlesmay, for example, have a solid structure, a porous structure, a hollowstructure, an aerogel structure, or the like, but are not limitedthereto.

The silicon oxide is capable of controlling the drying (or curing) rateof the adhesive composition according to some embodiments. For example,the silicon oxide may supply oxygen to a coating layer formed using theadhesive composition according to some embodiments. Accordingly, thesilicon oxide is capable of improving the drying (or curing) rate of theadhesive composition according to some embodiments and improvingadhesive strength by inducing a homogeneous reaction between the surfaceand the inside of the coating layer.

In some embodiments, the content of the silicon oxide may be about 0.01wt % to about 20 wt % with respect to 100 wt % of the adhesivecomposition. Preferably, the content of the silicon oxide may be about 1wt % to about 10 wt % with respect to 100 wt % of the adhesivecomposition. When the content of the silicon oxide is excessively low,the curing rate may decrease and curing may be heterogeneous. When thecontent of the silicon oxide is excessively high, sufficient adhesivestrength cannot be provided.

The adhesive composition according to some embodiments may furthercontain graphene oxide (GO). The graphene oxide may, for example,include a graphene oxide nano-powder.

The graphene oxide is capable of controlling the drying (or curing) rateof the adhesive composition according to some embodiments. For example,the graphene oxide may supply oxygen to a coating layer formed using theadhesive composition according to some embodiments. Accordingly, thegraphene oxide is capable of improving the drying (or curing) rate ofthe adhesive composition according to some embodiments and improvingadhesive strength by inducing a homogeneous reaction between the surfaceand the inside of the coating layer.

In some embodiments, the content of the graphene oxide may be about 0.01wt % to about 20 wt % with respect to 100 wt % of the adhesivecomposition. Preferably, the content of the graphene oxide may be about1 wt % to about 10 wt % with respect to 100 wt % of the adhesivecomposition. When the content of the graphene oxide is excessively low,the curing rate may decrease and curing may be heterogeneous. When thecontent of the graphene oxide is excessively high, sufficient adhesivestrength cannot be provided.

The adhesive composition according to some embodiments may be providedin a powder form. For example, the adhesive composition according tosome embodiments may not contain the solvent. The adhesive compositionprovided in the form of a powder has excellent storage and transportproperties, and thus may improve the productivity of products using theadhesive composition.

In some embodiments, the adhesive composition provided in a powder formmay be obtained through lyophilization (freeze-drying). In this regard,a method for preparing the adhesive composition will be described inmore detail later.

As described above, the adhesive composition according to someembodiments has excellent adhesive strength and is easily removed bywater because it is a water-soluble adhesive which is cured by ahydrogen bond, and is environmentally friendly due to the absence ofharmful substances therein and reduced outgassing. For example, theadhesive composition according to some embodiments has advantages ofreduced outgassing and increased environmental friendliness compared toan epoxy-based adhesive that is not easily removed or contains a harmfulsubstance (e.g., styrene or bisphenol A). In addition, for example, theadhesive composition according to some embodiments has an advantage ofhaving strong adhesive strength compared to a cyano acrylate-basedadhesive having weak adhesive strength.

Method for Preparing Adhesive Composition

Hereinafter, a method for preparing an adhesive composition according toexemplary embodiments will be described with reference to FIG. 1.

FIG. 1 is a flowchart illustrating a method for preparing an adhesivecomposition according to some embodiments.

Referring to FIG. 1, a method for preparing an adhesive compositionaccording to some embodiments may include providing an aqueouspolyphenol solution (step S10), providing an aqueous polymer solution(step S20), mixing the aqueous polyphenol solution with the aqueouspolymer solution to form a mixed aqueous solution (step S30), drying themixed aqueous solution to form a powder composition (step S40), anddissolving the powder composition in a solvent (step S50).

The aqueous polyphenol solution may contain the tannic acid. In someembodiments, the aqueous polyphenol solution may contain about 5% toabout 80 wt % of the tannic acid and the balance of water. Preferably,the aqueous polyphenol solution may contain about 10% to about 40 wt %of the tannic acid and the balance of water.

The aqueous polymer solution may contain the polyvinyl alcohol. In someembodiments, the aqueous polymer solution may contain about 5% to about80 wt % of the polyvinyl alcohol and the balance of water. Preferably,the aqueous polymer solution may contain about 10% to about 40 wt % ofthe polyvinyl alcohol and the balance of water.

In some embodiments, the ratio of the weight of the polyvinyl alcohol tothe weight of the tannic acid may be about 0.1 to about 10. Preferably,the ratio of the weight of the polyvinyl alcohol to the weight of thetannic acid may be about 0.5 to about 2.

Subsequently, the aqueous polyphenol solution may be mixed with theaqueous polymer solution (step S30). As a result, a mixed aqueoussolution containing the tannic acid and the polyvinyl alcohol may beformed.

In some embodiments, the mixed aqueous solution may further contain thesilicon oxide and/or the graphene oxide.

Subsequently, the mixed aqueous solution may be dried (step S40). Whenthe mixed aqueous solution is dried, a powder composition provided in apowder form may be formed. The powder composition may not contain asolvent (water). For example, the powder composition may contain about50 wt % of the tannic acid and about 50 wt % of the polyvinyl alcohol.

In some embodiments, forming the powder composition (S40) may includelyophilizing (or freeze-drying) the mixed aqueous solution. For example,the mixed aqueous solution may be frozen, the pressure may be reduced tosublimate the water from a solid to a gas and the sublimated water maybe removed to dry the mixed aqueous solution. Subsequently, the driedmixed aqueous solution may be ground to provide the powder composition.Accordingly, the adhesive composition according to some embodiments maybe provided in a powder form.

Subsequently, the powder composition may be dissolved in a solvent (stepS50). The solvent may include water and alcohol. For example, thesolvent may be provided by adding alcohol as a co-solvent to water. Thealcohol may, for example, be ethanol, but is not limited thereto.Accordingly, the adhesive composition according to some embodiments maybe provided in the form of a liquid mixture.

In some embodiments, the ratio of the weight of the alcohol to theweight of the water may be about 0.1 to about 10. Preferably, the ratioof the weight of the alcohol to the weight of the water may be about 0.5to about 2.

The adhesive composition according to some embodiments may contain about5% to about 45 wt % of the tannic acid, about 5% to about 45 wt % of thepolyvinyl alcohol, and the balance of the solvent. Preferably, theadhesive composition according to some embodiments may contain about 10%to about 40 wt % of the tannic acid, about 10% to about 40 wt % of thepolyvinyl alcohol, and the balance of the solvent.

Hereinafter, the effects of the adhesive composition according toexemplary embodiments will be described in more detail with reference toFIGS. 2 to 5, Preparation Examples and Comparative Examples.

PREPARATION EXAMPLE 1

Tannic acid (TA) was added to double distilled water (DDW), followed bystirring for 4 hours using a shaker to prepare an aqueous polyphenolsolution containing 20 wt % of tannic acid.

In addition, polyvinyl alcohol (PVA) was added to double distilled water(DDW), followed by stirring at 70° C. for 24 hours using a shaker toprovide an aqueous polymer solution containing 20 wt % of polyvinylalcohol (PVA).

Subsequently, the aqueous polyphenol solution was mixed with the aqueouspolymer solution at a ratio of 1:1, followed by vigorously stirring forseveral minutes to prepare 50 mL of an opaque browntannic-acid/polyvinyl-alcohol complex.

Subsequently, the tannic-acid/polyvinyl-alcohol complex was immersed inliquid nitrogen (about −196° C.), frozen and lyophilized to removemoisture, and the residue was ground using a grinder (or mortar) toprepare a composition as a powder.

Subsequently, the powder composition was added to a solvent of water andethanol, which were mixed in a ratio of 1:1, followed by stirring, toprepare an adhesive composition containing 20 wt % of the powdercomposition.

COMPARATIVE EXAMPLE 1

A gel-type adhesive composition was prepared by centrifuging the opaqueprecipitate of the tannic-acid/polyvinyl-alcohol complex prepared inPreparation Example 1.

COMPARATIVE EXAMPLE 2

DP-460-EG produced by 3M Corp. was used as an epoxy-based adhesive.

Physical Property Evaluation 1

The pot life, elastic modulus (E-modulus), lap shear strength, andtensile strength of each of Preparation Example 1, Comparative Example 1and Comparative Example 2 were measured, and the results are shown inTable 1 below.

TABLE 1 Preparation Comparative Comparative Example 1 Example 1 Example2 Pot life >1 day <1 day <30 min E-modulus (GPa) 0.35 — 1.8~2.6 Lapshear strength  7.5~11.1 >1 >10 (MPa) Tensile strength 2.9~4.7 0.067 <5(MPa)

As can be seen from Table 1 above, the adhesive composition preparedaccording to Preparation Example 1 exhibits a prolonged pot lifecompared to Comparative Example 1 and Comparative Example 2. The potlife of Preparation Example 1 can be greater than a day, or even greaterthan 3 days, or even 1 week or more, while remaining homogenouslydissolved and without undergoing phase separation. In particular, theadhesive composition prepared according to Comparative Example 1exhibited a continuous phase separation phenomenon, such as formation ofan aqueous layer as an upper layer, over time. Accordingly, it can beseen that the adhesive composition according to some embodiments hasprolonged pot life due to the use of the solvent including the alcoholas a co-solvent.

In addition, as can be seen from Table 1 above, the adhesive compositionprepared according to Preparation Example 1 exhibits lap shear strengthand tensile strength similar to that of Comparative Example 2. As can beseen in Table 1, both Preparation Example 1 and Comparative Example 2(epoxy based adhesive) can have a lap shear strength of greater than 10MPa and also have a tensile strength of less than 5 MPa. Accordingly, itcan be seen that the adhesive composition according to some embodimentshas high adhesive strength comparable to that of an epoxy-basedadhesive.

PREPARATION EXAMPLE 2

An adhesive composition was prepared in a manner similar to that ofPreparation Example 1, except that the powder composition was added inan amount of 40 wt % (with respect to 100 wt % of the adhesivecomposition) in Preparation Example 1.

PREPARATION EXAMPLE 3

An adhesive composition was prepared in a manner similar to that ofPreparation Example 2, except that silicon oxide particles (silicaparticles) were further added in an amount of 1 wt % (with respect to100 wt % of the adhesive composition) in Preparation Example 2.

PREPARATION EXAMPLE 4

An adhesive composition was prepared in a manner similar to that ofPreparation Example 2, except that silicon oxide particles (silicaparticles) were further added in an amount of 5 wt % (with respect to100 wt % of the adhesive composition) in Preparation Example 2.

PREPARATION EXAMPLE 5

An adhesive composition was prepared in a manner similar to that ofPreparation Example 2, except that silicon oxide particles (silicaparticles) were further added in an amount of 10 wt % (with respect to100 wt % of the adhesive composition) in Preparation Example 2.

PREPARATION EXAMPLE 6

An adhesive composition was prepared in a manner similar to that ofPreparation Example 2, except that graphene oxide (GO) was further addedin an amount of 1 wt % (with respect to 100 wt % of the adhesivecomposition) in Preparation Example 2.

PREPARATION EXAMPLE 7

An adhesive composition was prepared in a manner similar to that ofPreparation Example 2, except that graphene oxide (GO) was further addedin an amount of 5 wt % (with respect to 100 wt % of the adhesivecomposition) in Preparation Example 2.

PREPARATION EXAMPLE 8

An adhesive composition was prepared in a manner similar to that ofPreparation Example 2, except that graphene oxide (GO) was further addedin an amount of 10 wt % (with respect to 100 wt % of the adhesivecomposition) in Preparation Example 2.

Physical Property Evaluation 2

The dynamic modulus, storage modulus (G′) and loss modulus (G″) ofPreparation Examples 2 to 8, and Comparative Examples 1 and 2 weremeasured at 1 Hz, and the results are shown in Table 2 below.

TABLE 2 Storage Modulus (G′) Loss Modulus (G″) Preparation Example 2147.10 236.40 Preparation Example 3 20.14 36.29 Preparation Example 4202.4 391.4 Preparation Example 5 39.69 77.79 Preparation Example 640.07 55.85 Preparation Example 7 66.25 118.8 Preparation Example 834.34 16.10 Comparative Example 1 133,200.00 104,700.00 ComparativeExample 2 4.156 77.29

As can be seen from Table 2 above, the adhesive composition preparedaccording to Preparation Examples 2 to 8 exhibits a remarkably decreaseddynamic modulus compared to Comparative Example 1. From Table 2, e.g. inpreparation examples 3 and 5-8, the storage modulus is in a range offrom 20 to 70 MPa, and the loss modulus is from 15 to 120 MPa, or e.g.in examples 3, 5, 6 and 8, the storage modulus can be in the range offrom about 20 to about 40 MPa, and the loss modulus can be in the rangeof from 15 to 80 MPa.

Accordingly, it can be seen that the adhesive compositions according tosome embodiments have controlled viscosity and thus increased usabilityin the adhesion process due to the use of the solvent including thealcohol as a co-solvent.

In addition, as can be seen from Table 2, each of the adhesivecompositions prepared according to Preparation Examples 2 to 8 exhibitsa dynamic modulus similar to that of Comparative Example 2. Accordingly,it can be seen that the adhesive compositions according to someembodiments have strong adhesive strength comparable to that of anepoxy-based adhesive.

In addition, as can be seen from Table 2 above, the adhesivecompositions prepared according to Preparation Examples 3 to 8 exhibitan increased dynamic modulus compared to Preparation Example 2.Accordingly, it can be seen that the adhesive compositions according tosome embodiments have increased adhesive strength because they furthercontain the silicon oxide or the graphene oxide.

Reticle Assembly

Hereinafter, a reticle assembly including an adhesive compositionaccording to exemplary embodiments will be described with reference toFIGS. 2 to 4.

FIG. 2 is a perspective view illustrating a reticle assembly includingan adhesive composition according to some embodiments. FIG. 3 is aschematic cross-sectional view illustrating the reticle assembly of FIG.2. For simplicity of description, redundant parts of the descriptionalready given above may be recapitulated or omitted.

Referring to FIGS. 2 and 3, the reticle assembly according to someembodiments may include a pellicle 100, a pellicle adhesive layer 115,and a photomask 200.

The photomask 200 may include a pattern (e.g., “F” shape in FIG. 2) forperforming a photolithography process.

The pellicle 100 may be disposed on the photomask 200. The pellicle 100may protect the photomask 200 from contamination by foreign matter suchas dust. In addition, the pellicle 100 may have a light transmittance totransmit light incident on and reflected from the photomask 200. Forexample, the pellicle 100 may include a frame 120 and a pelliclemembrane 160.

The pellicle membrane 160 may be provided in the form of a layer spacedapart from the photomask 200. The pellicle membrane 160 may have a lighttransmittance. For example, the pellicle membrane 160 may have atransmittance to extreme ultraviolet (EUV) light of about 80% or more,and preferably about 90%. The pellicle membrane 160 may include any ofvarious materials having high transmittance to light (e.g., extremeultraviolet light).

In some embodiments, the pellicle membrane 160 may be spaced from thephotomask 200 by a distance of about 1 mm to about 10 mm. Although theframe 120 is illustrated to have a rectangular shape in plan view, thisis provided only as an example, and the frame 120 may have any ofvarious shapes, such as a circular shape.

In some embodiments, the pellicle membrane 160 may include silicon. Forexample, the pellicle membrane 160 may include polycrystalline silicon,single crystal silicon, silicon nitride, or a combination thereof.

In some embodiments, the pellicle membrane 160 may include acarbon-based material. For example, the pellicle membrane 160 mayinclude amorphous carbon, graphene, nanometer-thickness graphite, carbonnanosheet, carbon nanotubes, silicon carbide (SiC), boron carbide (B₄C),or a combination thereof. For example, the pellicle membrane 160 mayinclude nanocrystalline graphene. The nanocrystalline graphene mayinclude a plurality of nano-scale crystal grains, and the crystal grainsmay include a two-dimensional carbon structure having an aromatic ringstructure. The size (length or diameter) of the crystal grains may beseveral hundred nanometers (nm) or less, for example, about 100 nm orless. The two-dimensional carbon structure may have a layered structurein which carbon atoms are arranged in two dimensions. The crystal grainsof the nanocrystalline graphene may include a defect. For example, thedefect may include at least one of a sp³ carbon (C) atom, a hydrogen (H)atom, an oxygen (O) atom, a nitrogen (N) atom, or carbon vacancy.

In some embodiments, the pellicle membrane 160 may include asemiconductor material having a two-dimensional crystal structure. Forexample, the pellicle membrane 160 may include transition metaldichalcogenide (TMD). For example, the transition metal dichalcogenidemay contain one metal element selected from Mo, W, Nb, V, Ta, Ti, Zr,Hf, Tc, Re, Cu, Ga, In, Sn, Ge and Pb, and one chalcogen elementselected from S , Se and Te.

In some embodiments, the pellicle membrane 160 may include afluorine-based polymer.

In some embodiments, the pellicle membrane 160 may have a monolayerstructure or a multilayer structure. For example, the pellicle membrane160 may have a multilayer structure including a combination of thematerials described above. In addition, the pellicle membrane 160 mayfurther include a protective layer that is bonded to one side or bothsides of the membrane layer and includes SiC, SiO₂, Si₃N₄, SiON, Y₂O₃,YN, Mo, Ru, Rh, BN, B₄C, B, or a combination thereof.

In some embodiments, the pellicle membrane 160 may have a thickness ofabout 200 nm or less. For example, the thickness of the pelliclemembrane 160 may be about 1 nm to about 100 nm.

The frame 120 may be disposed along the edge of the photomask 200.Accordingly, the frame 120 may expose the pattern of the photomask 200(for example, “F” shape in FIG. 2).

The frame 120 may support the pellicle membrane 160 such that thepellicle membrane 160 is spaced apart from the photomask 200 by apredetermined distance. For example, a membrane boundary 150 may beformed along the edge of the pellicle membrane 160. The membraneboundary 150 may be adhered onto the frame 120 by a membrane adhesivelayer 155. As a result, the pellicle membrane 160 may be fixed on theframe 120.

In some embodiments, the membrane adhesive layer 155 may be formed usingthe adhesive composition described above. For example, the membraneadhesive layer 155 may include the polyphenol compound including tannicacid and the polymer including polyvinyl alcohol.

The frame 120 may include any of various materials capable of supportingthe pellicle membrane 160. For example, the frame 120 may include ametal having excellent heat dissipation and strength, but is not limitedthereto. For example, the frame 120 may include aluminum (Al), anodicaluminum oxide, stainless use steel (SUS), diamond-like carbon(DLC)-treated aluminum, DLC-treated SUS, silicon or a combinationthereof.

The frame 120 may be fixed on the photomask 200. In some embodiments,the frame 120 may be fixed on the photomask 200 by a stud 110, a firstfixture 130 and a second fixture 140. For example, the stud 110 may bedisposed such that the stud 110 protrudes from the upper surface of thephotomask 200. In addition, the first fixture 130 and the second fixture140 may be disposed such that the first fixture 130 and the secondfixture 140 are fastened to the frame 120. The first fixture 130 maypass through the frame 120 so as to be fastened to the stud 110. Thesecond fixture 140 may be disposed on the stud 110 so as to fix the stud110 fastened to the first fixture 130. As a result, the pellicle 100 maybe fixed on the photomask 200.

In some embodiments, the stud 110 may be adhered onto the photomask 200by the pellicle adhesive layer 115. As a result, the pellicle 100 may befixed on the photomask 200.

In some embodiments, the pellicle adhesive layer 115 may be formed usingthe adhesive composition described above. For example, the pellicleadhesive layer 115 may include the polyphenol compound including tannicacid and the polymer containing polyvinyl alcohol.

In some embodiments, the first fixture 130 may be adhered onto the frame120 by a fixture adhesive layer 135. As a result, the first fixture 130may be fixed on the frame 120.

In some embodiments, the fixture adhesive layer 135 may be formed usingthe adhesive composition described above. For example, the fixtureadhesive layer 135 may include the polyphenol compound including tannicacid and the polymer including polyvinyl alcohol.

FIG. 4 is a conceptual diagram illustrating exposure equipment using thereticle assembly of FIGS. 2 and 3. For simplicity of description,redundant parts of the description already given above may berecapitulated or omitted.

Referring to FIG. 4, the exposure equipment using the reticle assemblyaccording to some embodiments may include a reticle stage 300, a lightirradiator 600, a mirror system 700, and a wafer stage 900.

In some embodiments, the exposure equipment may perform a reflectivephotolithography process using the reticle assembly including thephotomask 200 and the pellicle 100.

The reticle assembly according to some embodiments may be mounted on thereticle stage 300. The reticle stage 300 may be movable, for example, ina horizontal direction to carry the reticle assembly according to someembodiments. The reticle assembly may be mounted on the reticle stage300 such that the pattern of the photomask 200 (e.g., “F” shape in FIG.2) faces the mirror system 700, which will be described later.

The light irradiator 600 may generate light L. The light irradiator 600may include a light source, a light collector and the like, but is notlimited thereto. In some embodiments, the light L generated from thelight irradiator 600 may include extreme ultraviolet (EUV) light. Forexample, the light irradiator 600 may generate light (e.g., extremeultraviolet light) having a wavelength of about 13.5 nm using carbonplasma. The light L generated by the light irradiator 600 may besupplied to the mirror system 700.

The mirror system 700 may include a plurality of contrast mirrors 750Aand a plurality of projection mirrors 750B. The contrast mirrors 750Aand the projection mirrors 750B may collect light L, for example, toprevent the reflected light L from being lost outside of an irradiationpath. For example, the contrast mirrors 750A may be concave mirrors.

The contrast mirrors 750A may supply the light L from the lightirradiator 600 to the reticle stage 300. The light L supplied from themirror system 700 by the contrast mirrors 750A may pass through thepellicle membrane 160 and may be irradiated on the photomask 200. Thelight L reflected from the photomask 200 may be supplied to theprojection mirrors 750B. Accordingly, the light incident on the patternof the photomask 200 (for example, “F” shape in FIG. 2) may be suppliedto the projection mirrors 750B. The projection mirrors 750B may receivelight L reflected from the photomask 200 and irradiate the light L to awafer W.

The wafer W may be loaded on the wafer stage 900. The wafer stage 900may be movable in, for example, a horizontal direction to carry thewafer W.

In some embodiments, a photoresist layer having a predeterminedthickness may be formed on the wafer W. Light L supplied from the mirrorsystem 700 may be projected onto the photoresist layer. For example, thefocus of the light L supplied from the mirror system 700 may be locatedwithin the photoresist layer. Accordingly, the photoresist layer may bepartially exposed based on optical pattern information (e.g., “F” shapein FIG. 2) of the photomask 200 to form a photoresist pattern. Inaddition, a layer formed on the wafer may be partially etched based onthe photoresist pattern to form a pattern on the wafer W.

Method for Fabricating Reticle Assembly

Hereinafter, a method for fabricating a reticle assembly including anadhesive composition according to exemplary embodiments will bedescribed with reference to FIGS. 2 to 11.

FIGS. 5 to 7 are diagrams illustrating the intermediate steps of amethod for fabricating a reticle assembly including an adhesivecomposition according to some embodiments. For simplicity ofdescription, redundant parts of the description already given above maybe recapitulated or omitted.

Referring to FIG. 4, a pellicle adhesive layer 115 is formed on aphotomask 200.

The pellicle adhesive layer 115 may be formed using the adhesivecomposition described above. For example, the adhesive composition maybe provided on the upper surface of the photomask 200.

The adhesive composition according to some embodiments may contain thepolyphenol compound including tannic acid, the polymer includingpolyvinyl alcohol, and the solvent including water and alcohol.

Referring to FIG. 6, a stud 110 is adhered onto the photomask 200 usingthe pellicle adhesive layer 115.

For example, the stud 110 may be disposed on the adhesive compositiondescribed above and then pressed. Subsequently, the adhesive compositionmay be dried in the state in which the adhesive composition contacts thestud 110. As a result, a cured pellicle adhesive layer 115 may be formedon the photomask 200, and the stud 110 may be adhered onto the photomask200.

In some embodiments, drying the adhesive composition as described abovemay be carried out at a temperature of about 100° C. or less. Forexample, drying the adhesive composition may include heating theadhesive composition to a temperature of about 60° C. to about 90° C.

Referring to FIG. 7, a frame 120 is fastened to the stud 110.

For example, the frame 120 may be disposed on the stud 110.Subsequently, a first fixture 130 may be formed such that the firstfixture 130 passes through the frame 120 so as to be fastened to thestud 110. Subsequently, a second fixture 140 may be disposed on the stud110 so as to fix the stud 110 fastened to the first fixture 130.

In some embodiments, the first fixture 130 may be adhered onto the frame120 by a fixture adhesive layer 135. As a result, the first fixture 130may be fixed on the frame 120.

In some embodiments, the fixture adhesive layer 135 may be formed usingthe adhesive composition described above. The adhesive compositionaccording to some embodiments may contain the polyphenol compoundincluding tannic acid, the polymer including polyvinyl alcohol, and thesolvent including water and alcohol.

Substantially, referring to FIG. 3, a pellicle membrane 160 is adheredonto the frame 120.

For example, the pellicle membrane 160 may be disposed on the frame 120such that the pellicle membrane 160 is spaced apart from the photomask200 by a predetermined distance. A membrane border 150 may be adheredonto the frame 120 by a membrane adhesive layer 155. As a result, thepellicle membrane 160 may be fixed on the frame 120.

In some embodiments, the membrane adhesive layer 155 may be formed usingthe adhesive composition described above. The adhesive compositionaccording to some embodiments may contain the polyphenol compoundincluding tannic acid, the polymer including polyvinyl alcohol, and thesolvent including water and alcohol.

While the present inventive concept has been particularly shown anddescribed with reference to exemplary embodiments thereof, it will beunderstood by those of ordinary skill in the art that various changes inform and details may be made therein without departing from the spiritand scope of the present inventive concept as defined by the followingclaims. It is therefore desired that the present embodiments beconsidered in all respects as illustrative and not restrictive,reference being made to the appended claims rather than the foregoingdescription to indicate the scope of the invention.

1. An adhesive composition comprising: a polyphenol compound includingtannic acid; a polymer including polyvinyl alcohol; and a solventincluding water and alcohol.
 2. The adhesive composition of claim 1,wherein the polymer contains hydrated polyvinyl alcohol.
 3. The adhesivecomposition of claim 1, wherein the alcohol contains ethanol.
 4. Theadhesive composition of claim 1, wherein a ratio of a weight of thepolyvinyl alcohol to a weight of the tannic acid is 0.5 to
 2. 5. Theadhesive composition of claim 1, wherein a ratio of a weight of thealcohol to a weight of the water is 0.5 to
 2. 6. The adhesivecomposition of claim 1, wherein with respect to 100 wt % of the adhesivecomposition, a content of the tannic acid is 5 wt % to 45 wt %, and acontent of the polyvinyl alcohol is 5 wt % to 45 wt %.
 7. The adhesivecomposition of claim 1, wherein the polyvinyl alcohol has a weightaverage molecular weight of 9,000 to 10,000.
 8. The adhesive compositionof claim 1, further comprising silicon oxide.
 9. The adhesivecomposition of claim 8, wherein with respect to 100 wt % of the adhesivecomposition, a content of the tannic acid is 5 wt % to 45 wt %, acontent of the polyvinyl alcohol is 5 wt % to 45 wt %, and a content ofthe silicon oxide is 0.01 wt % to 20 wt %.
 10. The adhesive compositionof claim 1, further comprising graphene oxide.
 11. The adhesivecomposition of claim 10, wherein with respect to 100 wt % of theadhesive composition, a content of the tannic acid is 5 wt % to 45 wt %,a content of the polyvinyl alcohol is 5 wt % to 45 wt %, and a contentof the graphene oxide is 0.01 wt % to 20 wt %.
 12. An adhesivecomposition in a powder form, comprising: a polyphenol compoundincluding tannic acid; and a polymer including polyvinyl alcohol. 13.The adhesive composition of claim 12, wherein a ratio of a weight of thepolyvinyl alcohol to a weight of the tannic acid is 0.5 to
 2. 14. Theadhesive composition of claim 13, wherein the adhesive composition doesnot contain a solvent.
 15. The adhesive composition of claim 12, whereinthe adhesive composition is prepared by lyophilization. 16-19.(canceled)
 20. A reticle assembly comprising: a photomask; a studprotruding from the photomask; a pellicle adhesive layer configured toadhere the stud onto the photomask; and a pellicle fixed on thephotomask by the stud, wherein the pellicle adhesive layer includes apolyphenol compound including tannic acid and a polymer includingpolyvinyl alcohol.
 21. reticle assembly of claim 20, wherein a ratio ofa weight of the polyvinyl alcohol to a weight of the tannic acid is 0.5to
 2. 22. The reticle assembly of claim 20, wherein the pellicleincludes: a pellicle membrane having a light transmittance; a frameconfigured to support the pellicle membrane; and a fixture configured topass through the frame to be fastened to the stud.
 23. The reticleassembly of claim 22, further comprising a membrane adhesive layerconfigured to adhere the pellicle membrane onto the frame.
 24. Thereticle assembly of claim 23, wherein the membrane adhesive layerincludes the polyphenol compound including tannic acid and the polymerincluding polyvinyl alcohol.
 25. (canceled)